Inverse-gas chromatography and the thermodynamics of sorption in polymers

In this review, the development of inverse gas chromatography (IGC) is briefly described, the role of A.A. Tager??s studies is indicated, and the principles of using the IGC method to solve problems of the thermodynamics of sorption of gases and vapors in polymers are formulated. The IGC method was originally developed by Guillet??s school to study the thermodynamics of sorption in polymers above their glass-transition temperatures; later, it was generalized and extended to the study of sorption processes below the glasstransition temperature in high-fractional free-volume polymers. These polymers exhibit specific features, such as strong exothermicity of mixing (??H _m ? 0), dependence of ??H _m on the size of the sorbate molecule, and high solubility coefficients. Chromatographic studies of sorption in the AF1600 amorphous perfluorinated polymer above and below its glass-transition temperature made it possible to test a new thermodynamic model that describes the sorption of gases and vapors in glassy polymers.